Clinical, Functional and Radiographic Outcomes of Primary Total Hip Arthroplasty between Direct Anterior Approach and Posterior Approach: a Systematic Review and Meta-analysis

Clinical, Functional and Radiographic Outcomes of Primary Total Hip Arthroplasty between Direct Anterior Approach and Posterior Approach: a Systematic Review and Meta-analysis | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research article Clinical, Functional and Radiographic Outcomes of Primary Total Hip Arthroplasty between Direct Anterior Approach and Posterior Approach: a Systematic Review and Meta-analysis Linbo Peng, Yi Zeng, Yuangang Wu, Junfeng Zeng, Yuan Liu, Bin Shen This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.2.21945/v3 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 02 Jun, 2020 Read the published version in BMC Musculoskeletal Disorders → Version 3 posted 4 You are reading this latest preprint version Show more versions Abstract Background: The purpose of this systematic review and meta-analysis was to compare the direct anterior approach and posterior approach for primary total hip arthroplasty in terms of the clinical, functional and radiographic outcomes. Methods: We searched the PubMed and EMBASE databases and Cochrane Library from their inception to November 1, 2019. We searched for previously published articles and meta-analyses of randomized controlled trials. Results: A total of 7 randomized controlled trials with 600 participants met the inclusion criteria. Among these patients, 301 and 299 were included in the DAA and PA groups, respectively. The DAA was associated with a longer surgery by a mean duration of 13.74 min (95% CI 6.88 to 20.61, p < 0.0001, I 2 =93%). The postoperative early functional outcomes were significantly better in the DAA group than in the PA group, such as the Visual Analogue Scale (VAS) score at 1 day postoperatively (MD=-0.65, 95% CI -0.91 to -0.38, p < 0.00001, I 2 =0%), VAS score at 2 days postoperatively (MD=-0.67, 95% CI -1.34 to -0.01, p =0.05, I 2 =88%) and Harris Hip Score (HHS) at 6 weeks postoperatively (MD=6.05, 95% CI 1.14 to 10.95, p =0.02, I 2 =52%). There was no significant difference between the DAA and PA groups in the length of the incision, hospital length of stay (LOS), blood loss, transfusion rates or complication rates. We found no significant difference between the two groups regarding late functional outcomes, such as the VAS score at 12 months postoperatively or the HHS scores at 3, 6, and 12 months postoperatively. A significant difference in the radiographic outcomes was not detected. Conclusions: The DAA requires a longer surgery time than does the PA in primary total hip arthroplasty. The DAA yields better early functional recovery than does the PA. There was no significant difference between the two groups in terms of other clinical, complication-related, late functional or radiographic outcomes. The evidence on the superiority of the DAA is insufficient and needs to be studied further. Orthopedics Total hip arthroplasty surgical approach direct anterior approach posterior approach early functional recovery. Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21 Figure 22 Figure 23 Figure 24 Background With the aging of society, the morbidity of knee and hip osteoarthritis is increasing rapidly, causing a large social and economic burden [ 1 , 2 ] . Total hip arthroplasty (THA) is the gold standard treatment for end-stage OA [ 3 ] . THA surgery has greatly improved the functional status of patients over the last half-century [ 4 ] . Many surgical approaches are used in THA surgery, but there is little evidence indicating which approach has the most advantages [ 5 , 6 ] . On the one hand, the direct anterior approach (DAA) is considered a true minimally invasive approach because it leads to a small amount of muscle damage, as the operation is performed through a small incision and a muscle interval in the hip joint [ 7 , 8 ] . On the other hand, the conventional posterior approach (PA) is the most frequently used surgical approach for THA [ 9 ] . Some studies show that compared with the PA, the DAA leads to less blood loss, low transfusion rates, shorter surgery times, a shorter length of hospital stay (LOS), low postoperative complication rates and better functional recovery [ 10-17 ] . Other studies have shown that DAA is associated with higher postoperative complication rates than is PA [ 18 , 19 ] , especially regarding neuropraxia in the lateral cutaneous nerve of the thigh [ 18 , 20 ] . Several meta-analyses have been published, but their results are not enough to be convincing. Retrospective studies and non-randomized controlled trials are included in most of the meta-analyses, which leads to indirect evidence [ 21-23 ] . Nonstandard approaches such as piriformis preserving approaches and those involving computer-aided technology were inappropriately regarded as standard approaches in some studies [ 21-25 ] , which should be strictly avoided for accurate results. Therefore, we performed a meta-analysis with strict inclusion criteria and includes the most recently published RCTs to compare the direct anterior approach and posterior approach for primary total hip arthroplasty in terms of the clinical, functional and radiographic outcomes. Methods Search strategies We performed this study in accordance with the Cochrane Handbook for Systematic Reviews of Interventions [ 26 ] and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines [ 27 ] . We searched the PubMed and EMBASE databases and Cochrane Library from their inception to November 1, 2019. We searched for previously published articles and meta-analyses of randomized controlled trials. We used the keywords "Arthroplasty, Replacement, Hip" and "approach" to identify published RCTs, and we did not use any language restrictions. The following electronic search strategy was used for PubMed: ((((((((((randomized controlled trial [pt]) OR controlled clinical trial [pt]) OR randomized [tiab]) OR placebo [tiab]) OR clinical trials as topic [mesh: noexp]) OR randomly [tiab]) OR trial [ti])) NOT ((animals [mh] NOT humans [mh])))) AND ((approach[Title/Abstract]) AND (((((((((((((((((((("Arthroplasty, Replacement, Hip"[Mesh]) OR Arthroplasties, Replacement, Hip[Title/Abstract]) OR Arthroplasty, Hip Replacement[Title/Abstract]) OR Hip Prosthesis Implantation[Title/Abstract]) OR Hip Prosthesis Implantations[Title/Abstract]) OR Implantation, Hip Prosthesis[Title/Abstract]) OR Implantations, Hip Prosthesis[Title/Abstract]) OR Prosthesis Implantation, Hip[Title/Abstract]) OR Prosthesis Implantations, Hip[Title/Abstract]) OR Hip Replacement Arthroplasty[Title/Abstract]) OR Replacement Arthroplasties, Hip[Title/Abstract]) OR Replacement Arthroplasty, Hip[Title/Abstract]) OR Arthroplasties, Hip Replacement[Title/Abstract]) OR Hip Replacement Arthroplasties[Title/Abstract]) OR Hip Replacement, Total[Title/Abstract]) OR Replacement, Total Hip[Title/Abstract]) OR Hip Replacements, Total[Title/Abstract]) OR Replacements, Total Hip[Title/Abstract]) OR Total Hip Replacements[Title/Abstract]) OR Total Hip Replacement[Title/Abstract])). Eligibility criteria (1) Participants: patients undergoing primary THA; (2) Interventions: the intervention group underwent THA surgery with the DAA; (3) Comparisons: the control group underwent THA surgery with the PA; (4) Outcomes: clinical outcomes such as the length of the incision, surgery time, length of hospital stay, blood loss, and transfusion rates; complications such as dislocation, fracture, LCNT neuropraxia, DVT and overall complications; radiographic outcomes such as acetabular inclination and acetabular anteversion; functional outcomes such as the VAS score at 1 day, 2 days, and 12 months postoperatively and the Harris hip score at 6 weeks, 3 months, 6 months, and 12 months postoperatively. (5) Study design: randomized controlled trials. Study selection We imported all the studies identified in the search into Endnote X7 software (Thompson Reuters, CA, USA). Two reviewers (LBP and JFZ) scanned the titles and abstracts independently, and we resolved any disagreements by discussion with senior reviewers. RCTs comparing the DAA and PA in THA surgery were eligible for inclusion. Duplicates were removed, and we also excluded commentaries, letters, case studies and reviews. Nonstandard approaches such as piriformis-preserving approaches, those involving computer-aided technology, or other surgical approaches were also excluded. Then, we read the full texts to exclude other ineligible studies. Data extraction Two authors extracted the following information and then reviewed the information together to guarantee the data were accurate: the name of the first author, publication year, study design, number of surgeons, number of cases in each group, follow-up duration, sex distribution, average age, BMI, learning cases, length of the incision, surgery duration, length of hospital stay, blood loss and transfusion rates, dislocation, fracture, LCNT neuropraxia, DVT and overall complication, acetabular inclination and acetabular anteversion, the VAS score at 1 day, 2 days, and 12 months postoperatively and the Harris hip score at 6 weeks, 3 months, 6 months, and 12 months postoperatively. Risk of bias in individual studies Two authors assessed the risk of bias for each article by the Cochrane Bias risk assessment tool. Disagreements were resolved by discussion with a senior researcher. We determined whether each study had a low, high or unclear risk of bias in each domain. Outcome measures and statistical analysis We conducted this study using Review Manager software 5.3. All the data were extracted into Excel first and then divided into categorical variables and continuous variables. Categorical variables (transfusion rates, complications (such as dislocation, fracture, LCNT neuropraxia, DVT and overall complication)) were expressed as odds ratios (ORs) with 95% confidence intervals CIs. Continuous variables (length of incision, surgery time, length of stay, blood loss, acetabular inclination, acetabular anteversion, the VAS score at 1 day, 2 days, and 12 months postoperatively and the Harris hip score at 6 weeks, 3 months, 6 months, and 12 months postoperatively) were expressed as the mean differences (MD) with 95% CIs. We used a fixed effects model when there was no statistical heterogeneity among the studies (p > 0.1, I² < 50%) and a random effects model when heterogeneity existed (p 50%). Otherwise, a descriptive analysis was used. The results of the meta-analysis were shown in forest plots; we considered p < 0.05 to indicate a statistically significant difference. Results Study selection We initially identified 969 studies and included 7 randomized controlled trials with 600 participants in the meta-analysis after screening for eligibility [ 18-20 , 28-31 ] . The PRISMA study flow diagram was shown in Fig. 1. Study characteristics A total of 7 randomized controlled trials with 600 participants were included. One study showed statistically significant differences between genders [ 28 ] , and one study did not provide BMI data [ 19 ] . None of the studies included learning cases. The demographic characteristics of the patients were shown in Table 1. Risk of bias All the studies included in the meta-analysis were randomized controlled trials of high quality. It is difficult to blind the doctors performing surgeries to the patient groups, but we think that the absence of blinding did not contribute to detection bias, at least in some outcome parameters. The risk of bias graph for each study and the risk of bias summary were shown in Fig. 2 and Fig. 3. Clinical outcomes Length of the incision Five studies [ 18-20 , 28 , 31 ] with a total of 503 patients were included in the comparison of the length of the incision between the DAA and PA in primary THA. We failed to find a significant difference between the DAA group and PA group, and there was statistically significant heterogeneity among the studies (MD=-2.79 cm, 95% CI -5.77 to 0.18, p = 0.07, I 2 =100%, Fig. 4). Surgery duration Six studies [ 18-20 , 28 , 30 , 31 ] with a total of 549 patients were included in the comparison of the surgery duration between the DAA and PA in primary THA. The DAA required a significantly longer surgery duration (13.74 min, 6.88 to 20.61, p<0.0001, Fig. 5), but there was statistically significant heterogeneity among the studies (I 2 =93%). Blood loss Four studies [ 20 , 28 , 30 , 31 ] with a total of 357 patients were included in the comparison of perioperative blood loss between the DAA and PA in primary THA. We failed to find a significant difference between the DAA group and PA group, and there was statistically significant heterogeneity among the studies (MD=58.96 ml, 95% CI -4.46 to 122.38, p = 0.07, I 2 =97%, Fig. 6). Transfusion rates Three studies [ 19 , 20 , 31 ] with a total of 344 patients were included in the comparison of the transfusion rates between the DAA and PA in primary THA. We failed to find a significant difference between the DAA group and PA group, and there was statistically significant heterogeneity among the studies (OR=0.35, 95% CI 0.04 to 3.15, p = 0.35, I 2 =87%, Fig. 7). Length of hospital stay (LOS) Six studies [ 18 , 19 , 28-31 ] with a total of 496 patients were included in the comparison of the LOS between the DAA and PA in primary THA. There was no significant difference between the DAA group and PA group in terms of the LOS (MD=-1.52 day, 95% CI -3.75 to 0.71, p = 0.18, Fig. 8). There was statistically significant heterogeneity among the studies (I 2 =100%). Complications Five studies [ 18-20 , 28 , 31 ] were included in the comparison of the complications between the DAA and PA in primary THA. Three studies [ 18 , 20 , 28 ] reported the occurrence of postoperative dislocation. There was no significant difference between the two groups in terms of the number of cases of dislocation (OR=0.52, 95% CI 0.09 to 3.08, p = 0.48, I 2 =0%, Fig. 9). Three studies [ 18 , 28 , 31 ] reported the occurrence of postoperative fractures. There was no significant difference between the two groups in terms of the number of fractures (OR=1.45, 95% CI 0.27 to 7.66, p = 0.67, I 2 =0%, Fig. 10). Three studies [ 18-20 ] reported the occurrence of postoperative DVT. There was no significant difference between the two groups in terms of the number of cases of DVT (OR=0.43, 95% CI 0.08 to 2.45, p = 0.34, I 2 =0%, Fig. 11). Two studies [ 18 , 20 ] reported the occurrence of postoperative LCNT neuropraxia. There was no significant difference between the two groups in terms of the number of cases of LCNT neuropraxia (OR=43.20, 95% CI 0.70 to 2654.71, p = 0.07, I 2 =74%, Fig. 12). Four studies [ 18-20 , 28 ] reported overall number of postoperative complications. There was no significant difference between the two groups in terms of the number of overall postoperative complications (OR=1.39, 95% CI 0.72 to 2.66, p = 0.32, I 2 =0%, Fig. 13). Functional outcomes VAS score Three studies [ 20 , 28 , 31 ] with a total of 311 patients were included in the comparison of the VAS score between the DAA and PA in primary THA. There was no significant difference between the two groups in terms of the preoperative VAS score (MD=-0.08, 95% CI -0.41 to 0.25, p = 0.62, I 2 =42%, Fig. 14). Two studies [ 28 , 31 ] reported the VAS score on 1st and 2nd day postoperatively. The DAA yield a significantly higher VAS score at 1st day postoperatively (MD=-0.65, -0.91 to -0.38, p<0.00001, I 2 =0%, Fig. 15). The DAA showed a significantly higher VAS score at 2nd days postoperatively (MD=-0.67, -1.34 to -0.01, p=0.05, I 2 =88%, Fig. 16), but there was statistically significant heterogeneity among the studies (I 2 =88%). Two studies [ 20 , 28 ] reported the VAS score at 12 months postoperatively. There was no significant difference between the two groups in terms of the VAS score at 12 months postoperatively (MD=-0.01, 95% CI -0.47 to 0.50, p = 0.96, I 2 =72%, Fig. 17). Harris Hip Score (HHS) Five studies [ 19 , 20 , 28 , 30 , 31 ] with a total of 477 patients were included in the comparison of the HHS score between the DAA and PA in primary THA. There was no significant difference between the two groups in terms of the preoperative HHS score (MD=-0.61, 95% CI -2.15 to 0.93, p = 0.44, I 2 =12%, Fig. 18). Two studies [ 28 , 30 ] reported the HHS score at 6 weeks postoperatively. The DAA yield a significantly higher HHS score at 6 weeks postoperatively (MD=6.05, 1.14 to 10.95, p=0.02, I 2 =52%, Fig. 19). Three studies [ 19 , 28 , 31 ] reported the HHS score at 3 months postoperatively. There was no significant difference between the two groups in terms of the HHS score at 3 months postoperatively (MD=6.30, 95% CI -1.70 to 14.31, p = 0.12, I 2 =89%, Fig. 20). Two studies [ 28 , 31 ] reported the HHS score at 6 months postoperatively. There was no significant difference between the two groups in terms of the HHS score at 6 months postoperatively (MD=0.67, 95% CI -1.87 to 3.21, p = 0.60, I 2 =0%, Fig. 21). Two studies [ 20 , 28 ] reported the HHS score at 12 months postoperatively. There was no significant difference between the two groups in terms of the HHS score at 12 months postoperatively (MD=0.65, 95% CI -1.16 to 2.46, p = 0.48, I 2 =0%, Fig. 22). Radiographic outcomes According to the Lewinnek safe zone (anteversion angle of 15°±10° and abduction angle of 40°±10°) [ 32 ] , we estimated the radiographic outcomes of the DAA and PA. Five studies [ 18-20 , 28 , 31 ] with a total of 503 patients were included in the comparison of the radiographic outcomes between the DAA and PA in primary THA. There was no significant difference between the two groups in the postoperative anteversion angle (MD=-0.01, 95% CI -4.21 to 4.20, p = 1.00, I 2 =96%, Fig. 23). Besides, there was no significant difference between the two groups in the postoperative abduction angle (MD=1.06, 95% CI -0.95 to 3.07, p = 0.30, I 2 =82%, Fig. 24). Discussion We performed this systematic review and meta-analysis of 7 randomized controlled trials with 600 participants to compare the DAA and PA in primary THA. In the comparison of the clinical outcomes, we found that the DAA was associated with a longer surgery by a mean duration of 13.74 min (95% CI 6.88 to 20.61, p < 0.0001, I 2 =93%). There was no significant difference between the DAA and PA groups in the length of the incision, length of hospital stay (LOS), blood loss, transfusion rates or complication rates. In the comparison of functional outcomes, the early functional outcomes were significantly better in the DAA group than in the PA group, such as the visual analogue scale (VAS) score at 1st day postoperatively (MD=-0.65, 95% CI -0.91 to -0.38, p < 0.00001, I 2 =0%), VAS score at 2nd days postoperatively (MD=-0.67, 95% CI -1.34 to -0.01, p =0.05, I 2 =88%) and Harris Hip Score (HHS) at 6 weeks postoperatively (MD=6.05, 95% CI 1.14 to 10.95, p =0.02, I 2 =52%). There was no significant difference between the two groups regarding the late functional outcomes, such as the VAS score at 12 months postoperatively or HHS scores at 3, 6, or 12 months postoperatively. Significant differences in the radiographic outcomes were not detected. To the best of the authors’ knowledge, this was the first meta-analysis of RCTs with direct evidence that comprehensively compared the clinical, functional and radiographic outcomes of primary total hip arthroplasty between the DAA and PA. In contrast to meta-analyses published in the past, our study only included RCTs and compared the clinical, functional and radiographic outcomes systematically, providing level I evidence of evidence-based medicine [ 33 ] . The meta-analysis by Miller et al [ 24 ] showed a shorter incision length, less pain experienced in the hospital, a lesser need for opioid medications and a shorter LOS in the DAA group than in the PA group. However, one study [ 34 ] in their meta-analysis compared the DAA and mini-posterior approach instead of the conventional PA, which may have increased the heterogeneity. Wang et al [ 25 ] reported a significantly shorter incision length and significantly less postoperative blood loss in the DAA group than in the PA group. They also found no significant difference in the operation time or rate of complications between the two groups. However, they included one nonrandomized study and one retrospective study in the meta-analyses, which decreased the reliability of the results. Jia et al [ 21 ] found a significantly shorter LOS and significantly longer surgery duration in the DAA group than in the PA group. The authors also included a mini-posterior approach study, which may have increased the level of heterogeneity. In another meta-analysis by Miller et al [ 23 ] , the DAA was found to be associated with a lower rate of infection, dislocation, and reoperation. However, most of their studies were retrospective, which inevitably led to bias. The LCNT neuropraxia outcomes varied among the studies, and only two RCTs [ 18 , 20 ] included in our study reported this specific complication. Some other researchers [ 14 , 21 , 34 ] reported different LCNT neuropraxia outcomes in non-RCTs. We believe this high level of heterogeneity may be due to the different levels of experience among the surgeons. In our study, early functional outcomes, such as the VAS score at 1st day postoperatively, VAS score at 2nd days postoperatively and HHS at 6 weeks postoperatively, were significantly better in the DAA group than in the PA group. Some other studies [ 21 , 22 , 25 ] also showed better early functional outcomes and lower pain scores in the DAA group. Our findings support this conclusion and increase the level of evidence. Due to a lack of more effective data, we failed to explore functional outcomes such as the EQ5D, 6MWT, WOMAC and HOOS results. In a comparison of the radiographic outcomes, Jia et al [ 21 ] also found that there were little differences in the prosthetic position between the two groups. There were nearly no statistically significant differences in the demographic characteristics of the patients in our meta-analysis. In addition, none of the studies were learning cases, which prevented this factor from influencing the results [ 35 ] . However, there was still high heterogeneity among most outcomes. We considered this result to be mainly due to the differences among the surgeons and the hospitals in how the surgical approaches were performed. The lack of a sufficient number of RCTs may be another important reason for the high heterogeneity. This study has several limitations. First, multiple comparisons were performed in our study, which may increase the risk of type 1 error. However, most of our test results were not significant, thereby demonstrating a low risk of type 1 error inflation. Second, the number of RCTs included in the study was insufficient, which might lead to inaccurate results. Third, some RCTs used unclear or high-risk allocation concealment and selective reporting methods, which may decrease the quality of the study. Fourth, available information about complications is insufficient. Therefore, the complication outcomes were not sufficiently reliable. Finally, we could not explore the intermediate-stage functional outcomes because of a lack of sufficient data. Conclusion The DAA requires a longer surgery duration than does the PA in primary total hip arthroplasty. The DAA yields improved early functional recovery compared with the PA. There was no significant difference between the two groups in terms of other clinical, complication-related, late functional or radiographic outcomes. The evidence on the superiority of the DAA is insufficient and needs to be investigated further. Abbreviations RCTs, randomized controlled trials; DAA, direct anterior approach; PA, posterior approach; THA, total hip arthroplasty; VAS, visual analogue scale; MD, mean deviation; CI, confidence interval; HHS, Harris hip score; LOS, length of stay; OA, osteoarthritis; PRISMA, preferred reporting items for systematic reviews and meta-analyses; LCNT, lateral cutaneous nerve of the thigh; USA, the United States of America; BMI, body mass index; OR, odds ratio; 6MWT, the 6-min walk test; WOMAC, the Western Ontario and McMaster Universities Osteoarthritis Index; HOOS, hip disability, and osteoarthritis outcome score; DVT, deep vein thrombosis. Declarations Ethics approval and consent to participate Ethical approval was not necessary because this study is a review of previous RCTs, and we did not obtain any other data from patients. The need for consent to participate is not applicable. Consent for publication Not applicable. Availability of data and material All data and materials are contained within the manuscript. Competing interests The authors Linbo Peng, Yi Zeng, Yuangang Wu, Junfeng Zeng, Yuan Liu, and Bin Shen declare that they have no conflicts of interest. Funding This study was not supported by any funding sources. Authors' contributions The following authors designed the study (BS), collected the data (LBP, JFZ), analysed the data (LBP, YL), wrote the initial drafts (LBP), and ensured the accuracy of the data and analysis (BS, YZ, YGW). All authors read and approved the manuscript. Acknowledgements All authors have approved this study for publication. References Cross M, Smith E, Hoy D, et al. The global burden of hip and knee osteoarthritis: estimates from the global burden of disease 2010 study. Ann Rheum Dis 2014; 73:1323-1330. Neuprez A, Neuprez AH, Kaux J-F, et al. 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Zhao HY, Kang PD, Xia YY, et al. Comparison of Early Functional Recovery After Total Hip Arthroplasty Using a Direct Anterior or Posterolateral Approach: A Randomized Controlled Trial. J Arthroplasty 2017; 32:3421-3428. Tezuka T, Heckmann ND, Bodner RJ, et al. Functional Safe Zone Is Superior to the Lewinnek Safe Zone for Total Hip Arthroplasty: Why the Lewinnek Safe Zone Is Not Always Predictive of Stability. J Arthroplasty 2019; 34:3-8. Kaefer M, Castagnetti M, Herbst K, et al. Evidence-based medicine III: level of evidence. J Pediatr Urol 2019; 15:407-408. Taunton MJ, Mason JB, Odum SM, et al. Direct anterior total hip arthroplasty yields more rapid voluntary cessation of all walking aids: a prospective, randomized clinical trial. J Arthroplasty 2014; 29:169-172. Kagan RP, Greber EM, Richards SM, et al. Advantages of an Anterior-Based Muscle-Sparing Approach in Transitioning From a Posterior Approach for Total Hip Arthroplasty: Minimizing the Learning Curve. J Arthroplasty 2019; 34:2962-2967. Table 1 Table 1. Study Year Study design Surgeon Number follow-up time Cases DAA : PA ages DAA:PA male/female DAA:PA BMI DAA:PA learning cases Barrett Cheng Christensen Luo Rykov Zhang Zhao 2013 2016 2015 2016 2017 2006 2017 RCT RCT RCT RCT RCT RCT RCT 1 2 1 1 3 Not clear Not clear 12 months 12 weeks 6weeks 16 months 6 weeks 30months 6 months 43:44 35:37 28:23 52:52 23:23 60:60 60:60 61.4 ± 9.2: 63.2 ± 7.7 59 : 62.5 64.3±9.1:65.2±9.1 61.5±7.2:63.7±6.8 62.8±6.1：60.2±8.1 61: 62.5 64.88±12.13:62.18±14.72 29/14: 19/25 15/20: 18/20 13/15: 11/12 17/35: 22/30 8/15: 11/12 25/35: 28/32 24/36: 26/34 30.7±5.4:29.1±5.0 27.7 28.3 31.1±5.1:30.4±3.6 22.7±4.4:24.2±3.7 29.0±5.6:29.3±4.8 not stated 24.3±53.1:25.58±2.83 NO NO NO NO NO NO NO Supplementary Files PRISMAchecklist.doc Cite Share Download PDF Status: Published Journal Publication published 02 Jun, 2020 Read the published version in BMC Musculoskeletal Disorders → Version 3 posted Editorial decision: Accept 27 Apr, 2020 Editor assigned by journal 20 Apr, 2020 Submission checks completed at journal 19 Apr, 2020 Editor invited by journal 19 Apr, 2020 You are reading this latest preprint version Show more versions Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-12527","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research article","associatedPublications":[],"authors":[{"id":510500,"identity":"bd67dba7-c8c8-470c-889a-7fd0f858c729","order_by":1,"name":"Linbo Peng","email":"","orcid":"","institution":"Sichuan University West China Hospital","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Linbo","middleName":"","lastName":"Peng","suffix":""},{"id":510501,"identity":"acd13a5b-8b1e-4b8b-bb5e-d9fc7b293688","order_by":2,"name":"Yi Zeng","email":"","orcid":"","institution":"Sichuan University West China 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17:05:21","currentVersionCode":3,"declarations":"","doi":"10.21203/rs.2.21945/v3","doiUrl":"https://doi.org/10.21203/rs.2.21945/v3","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12891-020-03318-x","type":"published","date":"2020-06-02T20:13:15+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":1026503,"identity":"c65d4a60-cce4-401b-88ef-d2e921f8058c","added_by":"auto","created_at":"2020-05-04 15:15:14","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":45598,"visible":true,"origin":"","legend":"PRISMA study flow diagram","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-12527/v3/1.jpg"},{"id":1026504,"identity":"8c74f6dc-1da7-4f83-8abb-4f9a828129b4","added_by":"auto","created_at":"2020-05-04 15:15:14","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":48461,"visible":true,"origin":"","legend":"Risk of 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THA","description":"","filename":"24.jpg","url":"https://assets-eu.researchsquare.com/files/rs-12527/v3/24.jpg"},{"id":13501285,"identity":"e23fe8c3-f717-49d7-a179-780110677519","added_by":"auto","created_at":"2021-09-16 23:09:51","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1082918,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-12527/v3/e5dfe8b7-5f27-43ee-a89d-f03bd29f1e6e.pdf"},{"id":1026502,"identity":"5a9a6062-4917-4f86-9bc7-6b55bbdabf48","added_by":"auto","created_at":"2020-05-04 15:15:14","extension":"doc","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":68608,"visible":true,"origin":"","legend":"","description":"","filename":"PRISMAchecklist.doc","url":"https://assets-eu.researchsquare.com/files/rs-12527/v3/PRISMAchecklist.doc"}],"financialInterests":"","formattedTitle":"Clinical, Functional and Radiographic Outcomes of Primary Total Hip Arthroplasty between Direct Anterior Approach and Posterior Approach: a Systematic Review and Meta-analysis","fulltext":[{"header":"Background","content":"\u003cp\u003eWith the aging of society, the morbidity of knee and hip osteoarthritis is increasing rapidly, causing a large social and economic burden\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_1\"\u003e\u003csup\u003e1\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_2\"\u003e\u003csup\u003e2\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e. Total hip arthroplasty (THA) is the gold standard treatment for end-stage OA\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_3\"\u003e\u003csup\u003e3\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e. THA surgery has greatly improved the functional status of patients over the last half-century\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_4\"\u003e\u003csup\u003e4\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eMany surgical approaches are used in THA surgery, but there is little evidence indicating which approach has the most advantages\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_5\"\u003e\u003csup\u003e5\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_6\"\u003e\u003csup\u003e6\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e. On the one hand, the direct anterior approach (DAA) is considered a true minimally invasive approach because it leads to a small amount of muscle damage, as the operation is performed through a small incision and a muscle interval in the hip joint\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_7\"\u003e\u003csup\u003e7\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_8\"\u003e\u003csup\u003e8\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e. On the other hand, the conventional posterior approach (PA) is the most frequently used surgical approach for THA\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_9\"\u003e\u003csup\u003e9\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eSome studies show that compared with the PA, the DAA leads to less blood loss, low transfusion rates, shorter surgery times, a shorter length of hospital stay (LOS), low postoperative complication rates and better functional recovery\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_10\"\u003e\u003csup\u003e10-17\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e. Other studies have shown that DAA is associated with higher postoperative complication rates than is PA\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_18\"\u003e\u003csup\u003e18\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_19\"\u003e\u003csup\u003e19\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e, especially regarding neuropraxia in the lateral cutaneous nerve of the thigh\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_18\"\u003e\u003csup\u003e18\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_20\"\u003e\u003csup\u003e20\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e. Several meta-analyses have been published, but their results are not enough to be convincing. Retrospective studies and non-randomized controlled trials are included in most of the meta-analyses, which leads to indirect evidence\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_21\"\u003e\u003csup\u003e21-23\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e. Nonstandard approaches such as piriformis preserving approaches and those involving computer-aided technology were inappropriately regarded as standard approaches in some studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_21\"\u003e\u003csup\u003e21-25\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e, which should be strictly avoided for accurate results. Therefore, we performed a meta-analysis with strict inclusion criteria and includes the most recently published RCTs to compare the direct anterior approach and posterior approach for primary total hip arthroplasty in terms of the clinical, functional and radiographic outcomes.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eSearch strategies\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe performed this study in accordance with the Cochrane Handbook for Systematic Reviews of Interventions \u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_26\"\u003e\u003csup\u003e26\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_27\"\u003e\u003csup\u003e27\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e. We searched the PubMed and EMBASE databases and Cochrane Library from their inception to November 1, 2019. We searched for previously published articles and meta-analyses of randomized controlled trials. We used the keywords \"Arthroplasty, Replacement, Hip\" and \"approach\" to identify published RCTs, and we did not use any language restrictions.\u003c/p\u003e\n\u003cp\u003eThe following electronic search strategy was used for PubMed: ((((((((((randomized controlled trial [pt]) OR controlled clinical trial [pt]) OR randomized [tiab]) OR placebo [tiab]) OR clinical trials as topic [mesh: noexp]) OR randomly [tiab]) OR trial [ti])) NOT ((animals [mh] NOT humans [mh])))) AND ((approach[Title/Abstract]) AND ((((((((((((((((((((\"Arthroplasty, Replacement, Hip\"[Mesh]) OR Arthroplasties, Replacement, Hip[Title/Abstract]) OR Arthroplasty, Hip Replacement[Title/Abstract]) OR Hip Prosthesis Implantation[Title/Abstract]) OR Hip Prosthesis Implantations[Title/Abstract]) OR Implantation, Hip Prosthesis[Title/Abstract]) OR Implantations, Hip Prosthesis[Title/Abstract]) OR Prosthesis Implantation, Hip[Title/Abstract]) OR Prosthesis Implantations, Hip[Title/Abstract]) OR Hip Replacement Arthroplasty[Title/Abstract]) OR Replacement Arthroplasties, Hip[Title/Abstract]) OR Replacement Arthroplasty, Hip[Title/Abstract]) OR Arthroplasties, Hip Replacement[Title/Abstract]) OR Hip Replacement Arthroplasties[Title/Abstract]) OR Hip Replacement, Total[Title/Abstract]) OR Replacement, Total Hip[Title/Abstract]) OR Hip Replacements, Total[Title/Abstract]) OR Replacements, Total Hip[Title/Abstract]) OR Total Hip Replacements[Title/Abstract]) OR Total Hip Replacement[Title/Abstract])).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEligibility criteria\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e(1) Participants: patients undergoing primary THA;\u003c/p\u003e\n\u003cp\u003e(2) Interventions: the intervention group underwent THA surgery with the DAA;\u003c/p\u003e\n\u003cp\u003e(3) Comparisons: the control group underwent THA surgery with the PA;\u003c/p\u003e\n\u003cp\u003e(4) Outcomes: clinical outcomes such as the length of the incision, surgery time, length of hospital stay, blood loss, and transfusion rates; complications such as dislocation, fracture, LCNT neuropraxia, DVT and overall complications; radiographic outcomes such as acetabular inclination and acetabular anteversion; functional outcomes such as the VAS score at 1 day, 2 days, and 12 months postoperatively and the Harris hip score at 6 weeks, 3 months, 6 months, and 12 months postoperatively.\u003c/p\u003e\n\u003cp\u003e(5) Study design: randomized controlled trials.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStudy selection\u0026nbsp; \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe imported all the studies identified in the search into Endnote X7 software (Thompson Reuters, CA, USA). Two reviewers (LBP and JFZ) scanned the titles and abstracts independently, and we resolved any disagreements by discussion with senior reviewers. RCTs comparing the DAA and PA in THA surgery were eligible for inclusion. Duplicates were removed, and we also excluded commentaries, letters, case studies and reviews. Nonstandard approaches such as piriformis-preserving approaches, those involving computer-aided technology, or other surgical approaches were also excluded. Then, we read the full texts to exclude other ineligible studies.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData extraction\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTwo authors extracted the following information and then reviewed the information together to guarantee the data were accurate: the name of the first author, publication year, study design, number of surgeons, number of cases in each group, follow-up duration, sex distribution, average age, BMI, learning cases, length of the incision, surgery duration, length of hospital stay, blood loss and transfusion rates, dislocation, fracture, LCNT neuropraxia, DVT and overall complication, acetabular inclination and acetabular anteversion, the VAS score at 1 day, 2 days, and 12 months postoperatively and the Harris hip score at 6 weeks, 3 months, 6 months, and 12 months postoperatively.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRisk of bias in individual studies\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp; \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTwo authors assessed the risk of bias for each article by the Cochrane Bias risk assessment tool. Disagreements were resolved by discussion with a senior researcher. We determined whether each study had a low, high or unclear risk of bias in each domain.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOutcome measures and statistical analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe conducted this study using Review Manager software 5.3. All the data were extracted into Excel first and then divided into categorical variables and continuous variables. Categorical variables (transfusion rates, complications (such as dislocation, fracture, LCNT neuropraxia, DVT and overall complication)) were expressed as odds ratios (ORs) with 95% confidence intervals CIs. Continuous variables (length of incision, surgery time, length of stay, blood loss, acetabular inclination, acetabular anteversion, the VAS score at 1 day, 2 days, and 12 months postoperatively and the Harris hip score at 6 weeks, 3 months, 6 months, and 12 months postoperatively) were expressed as the mean differences (MD) with 95% CIs. We used a fixed effects model when there was no statistical heterogeneity among the studies (p \u0026gt; 0.1, I\u0026sup2; \u0026lt; 50%) and a random effects model when heterogeneity existed (p \u0026lt; 0.1, I\u0026sup2; \u0026gt; 50%). Otherwise, a descriptive analysis was used. The results of the meta-analysis were shown in forest plots; we considered p \u0026lt; 0.05 to indicate a statistically significant difference.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003eStudy selection\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe initially identified 969 studies and included 7 randomized controlled trials with 600 participants in the meta-analysis after screening for eligibility\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_18\"\u003e\u003csup\u003e18-20\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_28\"\u003e\u003csup\u003e28-31\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e. The PRISMA study flow diagram was shown in Fig. 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStudy characteristics\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA total of 7 randomized controlled trials with 600 participants were included. One study showed statistically significant differences between genders\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_28\"\u003e\u003csup\u003e28\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e, and one study did not provide BMI data\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_19\"\u003e\u003csup\u003e19\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e. None of the studies included learning cases. The demographic characteristics of the patients were shown in Table 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRisk of bias\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll the studies included in the meta-analysis were randomized controlled trials of high quality. It is difficult to blind the doctors performing surgeries to the patient groups, but we think that the absence of blinding did not contribute to detection bias, at least in some outcome parameters. The risk of bias graph for each study and the risk of bias summary were shown in Fig. 2 and Fig. 3.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical outcomes\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLength of the incision\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFive studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_18\"\u003e\u003csup\u003e18-20\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_28\"\u003e\u003csup\u003e28\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_31\"\u003e\u003csup\u003e31\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e with a total of 503 patients were included in the comparison of the length of the incision between the DAA and PA in primary THA. We failed to find a significant difference between the DAA group and PA group, and there was statistically significant heterogeneity among the studies (MD=-2.79 cm, 95% CI -5.77 to 0.18, p = 0.07, I\u003csup\u003e2\u003c/sup\u003e=100%, Fig. 4).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSurgery duration\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSix studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_18\"\u003e\u003csup\u003e18-20\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_28\"\u003e\u003csup\u003e28\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_30\"\u003e\u003csup\u003e30\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_31\"\u003e\u003csup\u003e31\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e with a total of 549 patients were included in the comparison of the surgery duration between the DAA and PA in primary THA. The DAA required a significantly longer surgery duration (13.74 min, 6.88 to 20.61, p\u0026lt;0.0001, Fig. 5), but there was statistically significant heterogeneity among the studies (I\u003csup\u003e2\u003c/sup\u003e=93%).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eBlood loss\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFour studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_20\"\u003e\u003csup\u003e20\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_28\"\u003e\u003csup\u003e28\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_30\"\u003e\u003csup\u003e30\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_31\"\u003e\u003csup\u003e31\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e with a total of 357 patients were included in the comparison of perioperative blood loss between the DAA and PA in primary THA. We failed to find a significant difference between the DAA group and PA group, and there was statistically significant heterogeneity among the studies (MD=58.96 ml, 95% CI -4.46 to 122.38, p = 0.07, I\u003csup\u003e2\u003c/sup\u003e=97%, Fig. 6).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTransfusion rates\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThree studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_19\"\u003e\u003csup\u003e19\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_20\"\u003e\u003csup\u003e20\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_31\"\u003e\u003csup\u003e31\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e with a total of 344 patients were included in the comparison of the transfusion rates between the DAA and PA in primary THA. We failed to find a significant difference between the DAA group and PA group, and there was statistically significant heterogeneity among the studies (OR=0.35, 95% CI 0.04 to 3.15, p = 0.35, I\u003csup\u003e2\u003c/sup\u003e=87%, Fig. 7).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLength of hospital stay (LOS)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSix studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_18\"\u003e\u003csup\u003e18\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_19\"\u003e\u003csup\u003e19\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_28\"\u003e\u003csup\u003e28-31\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e with a total of 496 patients were included in the comparison of the LOS between the DAA and PA in primary THA. There was no significant difference between the DAA group and PA group in terms of the LOS (MD=-1.52 day, 95% CI -3.75 to 0.71, p = 0.18, Fig. 8). There was statistically significant heterogeneity among the studies (I\u003csup\u003e2\u003c/sup\u003e=100%).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eComplications\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFive studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_18\"\u003e\u003csup\u003e18-20\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_28\"\u003e\u003csup\u003e28\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_31\"\u003e\u003csup\u003e31\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e were included in the comparison of the complications between the DAA and PA in primary THA. Three studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_18\"\u003e\u003csup\u003e18\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_20\"\u003e\u003csup\u003e20\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_28\"\u003e\u003csup\u003e28\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e reported the occurrence of postoperative dislocation. There was no significant difference between the two groups in terms of the number of cases of dislocation (OR=0.52, 95% CI 0.09 to 3.08, p = 0.48, I\u003csup\u003e2\u003c/sup\u003e=0%, Fig. 9). Three studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_18\"\u003e\u003csup\u003e18\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_28\"\u003e\u003csup\u003e28\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_31\"\u003e\u003csup\u003e31\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e reported the occurrence of postoperative fractures. There was no significant difference between the two groups in terms of the number of fractures (OR=1.45, 95% CI 0.27 to 7.66, p = 0.67, I\u003csup\u003e2\u003c/sup\u003e=0%, Fig. 10). Three studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_18\"\u003e\u003csup\u003e18-20\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e reported the occurrence of postoperative DVT. There was no significant difference between the two groups in terms of the number of cases of DVT (OR=0.43, 95% CI 0.08 to 2.45, p = 0.34, I\u003csup\u003e2\u003c/sup\u003e=0%, Fig. 11). Two studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_18\"\u003e\u003csup\u003e18\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_20\"\u003e\u003csup\u003e20\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e reported the occurrence of postoperative LCNT neuropraxia. There was no significant difference between the two groups in terms of the number of cases of LCNT neuropraxia (OR=43.20, 95% CI 0.70 to 2654.71, p = 0.07, I\u003csup\u003e2\u003c/sup\u003e=74%, Fig. 12). Four studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_18\"\u003e\u003csup\u003e18-20\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_28\"\u003e\u003csup\u003e28\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e reported overall number of postoperative complications. There was no significant difference between the two groups in terms of the number of overall postoperative complications (OR=1.39, 95% CI 0.72 to 2.66, p = 0.32, I\u003csup\u003e2\u003c/sup\u003e=0%, Fig. 13).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunctional outcomes\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eVAS score\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThree studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_20\"\u003e\u003csup\u003e20\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_28\"\u003e\u003csup\u003e28\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_31\"\u003e\u003csup\u003e31\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e with a total of 311 patients were included in the comparison of the VAS score between the DAA and PA in primary THA. There was no significant difference between the two groups in terms of the preoperative VAS score (MD=-0.08, 95% CI -0.41 to 0.25, p = 0.62, I\u003csup\u003e2\u003c/sup\u003e=42%, Fig. 14). Two studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_28\"\u003e\u003csup\u003e28\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_31\"\u003e\u003csup\u003e31\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e reported the VAS score on 1st and 2nd day postoperatively. The DAA yield a significantly higher VAS score at 1st day postoperatively (MD=-0.65, -0.91 to -0.38, p\u0026lt;0.00001, I\u003csup\u003e2\u003c/sup\u003e=0%, Fig. 15). The DAA showed a significantly higher VAS score at 2nd days postoperatively (MD=-0.67, -1.34 to -0.01, p=0.05, I\u003csup\u003e2\u003c/sup\u003e=88%, Fig. 16), but there was statistically significant heterogeneity among the studies (I\u003csup\u003e2\u003c/sup\u003e=88%). Two studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_20\"\u003e\u003csup\u003e20\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_28\"\u003e\u003csup\u003e28\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e reported the VAS score at 12 months postoperatively. There was no significant difference between the two groups in terms of the VAS score at 12 months postoperatively (MD=-0.01, 95% CI -0.47 to 0.50, p = 0.96, I\u003csup\u003e2\u003c/sup\u003e=72%, Fig. 17).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eHarris Hip Score (HHS)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFive studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_19\"\u003e\u003csup\u003e19\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_20\"\u003e\u003csup\u003e20\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_28\"\u003e\u003csup\u003e28\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_30\"\u003e\u003csup\u003e30\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_31\"\u003e\u003csup\u003e31\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e with a total of 477 patients were included in the comparison of the HHS score between the DAA and PA in primary THA. There was no significant difference between the two groups in terms of the preoperative HHS score (MD=-0.61, 95% CI -2.15 to 0.93, p = 0.44, I\u003csup\u003e2\u003c/sup\u003e=12%, Fig. 18). Two studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_28\"\u003e\u003csup\u003e28\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_30\"\u003e\u003csup\u003e30\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e reported the HHS score at 6 weeks postoperatively. The DAA yield a significantly higher HHS score at 6 weeks postoperatively (MD=6.05, 1.14 to 10.95, p=0.02, I\u003csup\u003e2\u003c/sup\u003e=52%, Fig. 19). Three studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_19\"\u003e\u003csup\u003e19\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_28\"\u003e\u003csup\u003e28\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_31\"\u003e\u003csup\u003e31\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e reported the HHS score at 3 months postoperatively. There was no significant difference between the two groups in terms of the HHS score at 3 months postoperatively (MD=6.30, 95% CI -1.70 to 14.31, p = 0.12, I\u003csup\u003e2\u003c/sup\u003e=89%, Fig. 20). Two studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_28\"\u003e\u003csup\u003e28\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_31\"\u003e\u003csup\u003e31\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e reported the HHS score at 6 months postoperatively. There was no significant difference between the two groups in terms of the HHS score at 6 months postoperatively (MD=0.67, 95% CI -1.87 to 3.21, p = 0.60, I\u003csup\u003e2\u003c/sup\u003e=0%, Fig. 21). Two studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_20\"\u003e\u003csup\u003e20\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_28\"\u003e\u003csup\u003e28\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e reported the HHS score at 12 months postoperatively. There was no significant difference between the two groups in terms of the HHS score at 12 months postoperatively (MD=0.65, 95% CI -1.16 to 2.46, p = 0.48, I\u003csup\u003e2\u003c/sup\u003e=0%, Fig. 22).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRadiographic outcomes\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAccording to the Lewinnek safe zone (anteversion angle of 15\u0026deg;\u0026plusmn;10\u0026deg; and abduction angle of 40\u0026deg;\u0026plusmn;10\u0026deg;)\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_32\"\u003e\u003csup\u003e32\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e, we estimated the radiographic outcomes of the DAA and PA. Five studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_18\"\u003e\u003csup\u003e18-20\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_28\"\u003e\u003csup\u003e28\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_31\"\u003e\u003csup\u003e31\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e with a total of 503 patients were included in the comparison of the radiographic outcomes between the DAA and PA in primary THA. There was no significant difference between the two groups in the postoperative anteversion angle (MD=-0.01, 95% CI -4.21 to 4.20, p = 1.00, I\u003csup\u003e2\u003c/sup\u003e=96%, Fig. 23). Besides, there was no significant difference between the two groups in the postoperative abduction angle (MD=1.06, 95% CI -0.95 to 3.07, p = 0.30, I\u003csup\u003e2\u003c/sup\u003e=82%, Fig. 24).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eWe performed this systematic review and meta-analysis of 7 randomized controlled trials with 600 participants to compare the DAA and PA in primary THA. In the comparison of the clinical outcomes, we found that the DAA was associated with a longer surgery by a mean duration of 13.74 min (95% CI 6.88 to 20.61, p \u0026lt; 0.0001, I\u003csup\u003e2\u003c/sup\u003e=93%). There was no significant difference between the DAA and PA groups in the length of the incision, length of hospital stay (LOS), blood loss, transfusion rates or complication rates. In the comparison of functional outcomes, the early functional outcomes were significantly better in the DAA group than in the PA group, such as the visual analogue scale (VAS) score at 1st day postoperatively (MD=-0.65, 95% CI -0.91 to -0.38, p \u0026lt; 0.00001, I\u003csup\u003e2\u003c/sup\u003e=0%), VAS score at 2nd days postoperatively (MD=-0.67, 95% CI -1.34 to -0.01, p =0.05, I\u003csup\u003e2\u003c/sup\u003e=88%) and Harris Hip Score (HHS) at 6 weeks postoperatively (MD=6.05, 95% CI 1.14 to 10.95, p =0.02, I\u003csup\u003e2\u003c/sup\u003e=52%). There was no significant difference between the two groups regarding the late functional outcomes, such as the VAS score at 12 months postoperatively or HHS scores at 3, 6, or 12 months postoperatively. Significant differences in the radiographic outcomes were not detected. To the best of the authors\u0026rsquo; knowledge, this was the first meta-analysis of RCTs with direct evidence that comprehensively compared the clinical, functional and radiographic outcomes of primary total hip arthroplasty between the DAA and PA.\u003c/p\u003e\n\u003cp\u003eIn contrast to meta-analyses published in the past, our study only included RCTs and compared the clinical, functional and radiographic outcomes systematically, providing level I evidence of evidence-based medicine\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_33\"\u003e\u003csup\u003e33\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e. The meta-analysis by Miller et al\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_24\"\u003e\u003csup\u003e24\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e showed a shorter incision length, less pain experienced in the hospital, a lesser need for opioid medications and a shorter LOS in the DAA group than in the PA group. However, one study\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_34\"\u003e\u003csup\u003e34\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e in their meta-analysis compared the DAA and mini-posterior approach instead of the conventional PA, which may have increased the heterogeneity. Wang et al\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_25\"\u003e\u003csup\u003e25\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e reported a significantly shorter incision length and significantly less postoperative blood loss in the DAA group than in the PA group. They also found no significant difference in the operation time or rate of complications between the two groups. However, they included one nonrandomized study and one retrospective study in the meta-analyses, which decreased the reliability of the results. Jia et al\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_21\"\u003e\u003csup\u003e21\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e found a significantly shorter LOS and significantly longer surgery duration in the DAA group than in the PA group. The authors also included a mini-posterior approach study, which may have increased the level of heterogeneity. In another meta-analysis by Miller et al\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_23\"\u003e\u003csup\u003e23\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e, the DAA was found to be associated with a lower rate of infection, dislocation, and reoperation. However, most of their studies were retrospective, which inevitably led to bias. The LCNT neuropraxia outcomes varied among the studies, and only two RCTs\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_18\"\u003e\u003csup\u003e18\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_20\"\u003e\u003csup\u003e20\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e included in our study reported this specific complication. Some other researchers\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_14\"\u003e\u003csup\u003e14\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_21\"\u003e\u003csup\u003e21\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_34\"\u003e\u003csup\u003e34\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e reported different LCNT neuropraxia outcomes in non-RCTs. We believe this high level of heterogeneity may be due to the different levels of experience among the surgeons. In our study, early functional outcomes, such as the VAS score at 1st day postoperatively, VAS score at 2nd days postoperatively and HHS at 6 weeks postoperatively, were significantly better in the DAA group than in the PA group. Some other studies\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_21\"\u003e\u003csup\u003e21\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_22\"\u003e\u003csup\u003e22\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e, \u003c/sup\u003e\u003ca href=\"#_ENREF_25\"\u003e\u003csup\u003e25\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e also showed better early functional outcomes and lower pain scores in the DAA group. Our findings support this conclusion and increase the level of evidence. Due to a lack of more effective data, we failed to explore functional outcomes such as the EQ5D, 6MWT, WOMAC and HOOS results. In a comparison of the radiographic outcomes, Jia et al\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_21\"\u003e\u003csup\u003e21\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e also found that there were little differences in the prosthetic position between the two groups.\u003c/p\u003e\n\u003cp\u003eThere were nearly no statistically significant differences in the demographic characteristics of the patients in our meta-analysis. In addition, none of the studies were learning cases, which prevented this factor from influencing the results\u003csup\u003e[\u003c/sup\u003e\u003ca href=\"#_ENREF_35\"\u003e\u003csup\u003e35\u003c/sup\u003e\u003c/a\u003e\u003csup\u003e]\u003c/sup\u003e. However, there was still high heterogeneity among most outcomes. We considered this result to be mainly due to the differences among the surgeons and the hospitals in how the surgical approaches were performed. The lack of a sufficient number of RCTs may be another important reason for the high heterogeneity.\u003c/p\u003e\n\u003cp\u003eThis study has several limitations. First, multiple comparisons were performed in our study, which may increase the risk of type 1 error. However, most of our test results were not significant, thereby demonstrating a low risk of type 1 error inflation. Second, the number of RCTs included in the study was insufficient, which might lead to inaccurate results. Third, some RCTs used unclear or high-risk allocation concealment and selective reporting methods, which may decrease the quality of the study. Fourth, available information about complications is insufficient. Therefore, the complication outcomes were not sufficiently reliable. Finally, we could not explore the intermediate-stage functional outcomes because of a lack of sufficient data.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe DAA requires a longer surgery duration than does the PA in primary total hip arthroplasty. The DAA yields improved early functional recovery compared with the PA. There was no significant difference between the two groups in terms of other clinical, complication-related, late functional or radiographic outcomes. The evidence on the superiority of the DAA is insufficient and needs to be investigated further.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eRCTs, randomized controlled trials; DAA, direct anterior approach; PA, posterior approach; THA, total hip arthroplasty; VAS, visual analogue scale; MD, mean deviation; CI, confidence interval; HHS, Harris hip score; LOS, length of stay; OA, osteoarthritis; PRISMA, preferred reporting items for systematic reviews and meta-analyses; LCNT, lateral cutaneous nerve of the thigh; USA, the United States of America; BMI, body mass index; OR, odds ratio; 6MWT, the 6-min walk test; WOMAC, the Western Ontario and McMaster Universities Osteoarthritis Index; HOOS, hip disability, and osteoarthritis outcome score; DVT, deep vein thrombosis.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEthical approval was not necessary because this study is a review of previous RCTs, and we did not obtain any other data from patients. The need for consent to participate is not applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and material\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data and materials are contained within the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors Linbo Peng, Yi Zeng, Yuangang Wu, Junfeng Zeng, Yuan Liu, and Bin Shen declare that they have no conflicts of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was not supported by any funding sources.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors' contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe following authors designed the study (BS), collected the data (LBP, JFZ), analysed the data (LBP, YL), wrote the initial drafts (LBP), and ensured the accuracy of the data and analysis (BS, YZ, YGW). All authors read and approved the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors have approved this study for publication.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eCross M, Smith E, Hoy D, et al. The global burden of hip and knee osteoarthritis: estimates from the global burden of disease 2010 study. Ann Rheum Dis 2014; 73:1323-1330.\u003c/li\u003e\n\u003cli\u003eNeuprez A, Neuprez AH, Kaux J-F, et al. Total joint replacement improves pain, functional quality of life, and health utilities in patients with late-stage knee and hip osteoarthritis for up to 5 years. Clin Rheumatol 2019:10.1007/s10067-019-04811-y.\u003c/li\u003e\n\u003cli\u003eKurtz S, Mowat F, Ong K, et al. Prevalence of primary and revision total hip and knee arthroplasty in the United States from 1990 through 2002. 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A systematic review and meta-analysis of direct anterior approach versus posterior approach in total hip arthroplasty. J Orthop Surg Res 2018; 13:229-229.\u003c/li\u003e\n\u003cli\u003eHiggins JPT TJ, Chandler J, Cumpston M, Li T, Page MJ, Welch VA (editors). Cochrane Handbook for Systematic Reviews of Interventions version 6.0 (updated July 2019). Cochrane. Available from \u003ca href=\"http://www.training.cochrane.org/handbook\"\u003ewww.training.cochrane.org/handbook\u003c/a\u003e. 2019.\u003c/li\u003e\n\u003cli\u003eLiberati A, Altman DG, Tetzlaff J, et al. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration. J Clin Epidemiol 2009; 62:e1-e34.\u003c/li\u003e\n\u003cli\u003eBarrett WP, Turner SE, Leopold JP. Prospective randomized study of direct anterior vs postero-lateral approach for total hip arthroplasty. J Arthroplasty 2013; 28:1634-8.\u003c/li\u003e\n\u003cli\u003eChristensen CP, Jacobs CA. Comparison of Patient Function during the First Six Weeks after Direct Anterior or Posterior Total Hip Arthroplasty (THA): A Randomized Study. J Arthroplasty 2015; 30:94-7.\u003c/li\u003e\n\u003cli\u003eRykov K, Reininga IHF, Sietsma MS, et al. Posterolateral vs Direct Anterior Approach in Total Hip Arthroplasty (POLADA Trial): A Randomized Controlled Trial to Assess Differences in Serum Markers. J Arthroplasty 2017; 32:3652-3658.e1.\u003c/li\u003e\n\u003cli\u003eZhao HY, Kang PD, Xia YY, et al. Comparison of Early Functional Recovery After Total Hip Arthroplasty Using a Direct Anterior or Posterolateral Approach: A Randomized Controlled Trial. J Arthroplasty 2017; 32:3421-3428.\u003c/li\u003e\n\u003cli\u003eTezuka T, Heckmann ND, Bodner RJ, et al. Functional Safe Zone Is Superior to the Lewinnek Safe Zone for Total Hip Arthroplasty: Why the Lewinnek Safe Zone Is Not Always Predictive of Stability. J Arthroplasty 2019; 34:3-8.\u003c/li\u003e\n\u003cli\u003eKaefer M, Castagnetti M, Herbst K, et al. Evidence-based medicine III: level of evidence. J Pediatr Urol 2019; 15:407-408.\u003c/li\u003e\n\u003cli\u003eTaunton MJ, Mason JB, Odum SM, et al. Direct anterior total hip arthroplasty yields more rapid voluntary cessation of all walking aids: a prospective, randomized clinical trial. J Arthroplasty 2014; 29:169-172.\u003c/li\u003e\n\u003cli\u003eKagan RP, Greber EM, Richards SM, et al. Advantages of an Anterior-Based Muscle-Sparing Approach in Transitioning From a Posterior Approach for Total Hip Arthroplasty: Minimizing the Learning Curve. J Arthroplasty 2019; 34:2962-2967.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Table 1","content":"\u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0); font-size: 10px; font-family: Verdana, Geneva, sans-serif;\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n\u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eTable 1.\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellpadding=\"0\" cellspacing=\"0\" style=\"width:468.45pt;border-collapse:collapse;border:none;\" width=\"625\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 69.75pt;border-top: 1.5pt solid windowtext;border-left: none;border-bottom: 1pt solid black;border-right: none;padding: 0in 5.4pt;height: 48.9pt;vertical-align: top;\" valign=\"top\" width=\"14.88%\"\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cstrong\u003eStudy\u003c/strong\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 35.3pt;border-top: 1.5pt solid windowtext;border-left: none;border-bottom: 1pt solid black;border-right: none;padding: 0in 5.4pt;height: 48.9pt;vertical-align: top;\" valign=\"top\" width=\"7.52%\"\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cstrong\u003eYear\u003c/strong\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 36.1pt;border-top: 1.5pt solid windowtext;border-left: none;border-bottom: 1pt solid black;border-right: none;padding: 0in 5.4pt;height: 48.9pt;vertical-align: top;\" valign=\"top\" width=\"7.68%\"\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cstrong\u003eStudy design\u003c/strong\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 43.5pt;border-top: 1.5pt solid windowtext;border-left: none;border-bottom: 1pt solid black;border-right: none;padding: 0in 5.4pt;height: 48.9pt;vertical-align: top;\" valign=\"top\" width=\"9.28%\"\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cstrong\u003eSurgeon\u003c/strong\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cstrong\u003eNumber\u003c/strong\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47.9pt;border-top: 1.5pt solid windowtext;border-left: none;border-bottom: 1pt solid black;border-right: none;padding: 0in 5.4pt;height: 48.9pt;vertical-align: top;\" valign=\"top\" width=\"10.24%\"\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cstrong\u003efollow-up time\u003c/strong\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 45pt;border-top: 1.5pt solid windowtext;border-left: none;border-bottom: 1pt solid black;border-right: none;padding: 0in 5.4pt;height: 48.9pt;vertical-align: top;\" valign=\"top\" width=\"9.6%\"\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cstrong\u003eCases\u003c/strong\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cstrong\u003eDAA\u003c/strong\u003e\u003cstrong\u003e:\u003c/strong\u003e\u003cstrong\u003ePA\u003c/strong\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 44.95pt;border-top: 1.5pt solid windowtext;border-left: none;border-bottom: 1pt solid black;border-right: none;padding: 0in 5.4pt;height: 48.9pt;vertical-align: top;\" valign=\"top\" width=\"9.6%\"\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cstrong\u003eages\u003c/strong\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cstrong\u003eDAA:PA\u003c/strong\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 57.85pt;border-top: 1.5pt solid windowtext;border-left: none;border-bottom: 1pt solid black;border-right: none;padding: 0in 5.4pt;height: 48.9pt;vertical-align: top;\" valign=\"top\" width=\"12.32%\"\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cstrong\u003emale/female\u003c/strong\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cstrong\u003eDAA:PA\u003c/strong\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 44.95pt;border-top: 1.5pt solid windowtext;border-left: none;border-bottom: 1pt solid black;border-right: none;padding: 0in 5.4pt;height: 48.9pt;vertical-align: top;\" valign=\"top\" width=\"9.6%\"\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cstrong\u003eBMI\u003c/strong\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cstrong\u003eDAA:PA\u003c/strong\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 43.15pt;border-top: 1.5pt solid windowtext;border-left: none;border-bottom: 1pt solid black;border-right: none;padding: 0in 5.4pt;height: 48.9pt;vertical-align: top;\" valign=\"top\" width=\"9.28%\"\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cstrong\u003elearning cases\u003c/strong\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 69.75pt;border-top: none;border-right: none;border-left: none;border-image: initial;border-bottom: 1.5pt solid windowtext;padding: 0in 5.4pt;height: 49.3pt;vertical-align: top;\" valign=\"top\" width=\"14.88%\"\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eBarrett\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eCheng\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eChristensen\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eLuo\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eRykov\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eZhang\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eZhao\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 35.3pt;border-top: none;border-right: none;border-left: none;border-image: initial;border-bottom: 1.5pt solid windowtext;padding: 0in 5.4pt;height: 49.3pt;vertical-align: top;\" valign=\"top\" width=\"7.52%\"\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e2013\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e2016\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e2015\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e2016\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e2017\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e2006\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e2017\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 36.1pt;border-top: none;border-right: none;border-left: none;border-image: initial;border-bottom: 1.5pt solid windowtext;padding: 0in 5.4pt;height: 49.3pt;vertical-align: top;\" valign=\"top\" width=\"7.68%\"\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eRCT\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eRCT\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eRCT\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eRCT\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eRCT\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eRCT\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eRCT\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 43.5pt;border-top: none;border-right: none;border-left: none;border-image: initial;border-bottom: 1.5pt solid windowtext;padding: 0in 5.4pt;height: 49.3pt;vertical-align: top;\" valign=\"top\" width=\"9.28%\"\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e1\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e2\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e1\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e1\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e3\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eNot clear\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eNot clear\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47.9pt;border-top: none;border-right: none;border-left: none;border-image: initial;border-bottom: 1.5pt solid windowtext;padding: 0in 5.4pt;height: 49.3pt;vertical-align: top;\" valign=\"top\" width=\"10.24%\"\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e12 months\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e12 weeks\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e6weeks\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e16 months\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e6 weeks\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e30months\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e6 months\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 45pt;border-top: none;border-right: none;border-left: none;border-image: initial;border-bottom: 1.5pt solid windowtext;padding: 0in 5.4pt;height: 49.3pt;vertical-align: top;\" valign=\"top\" width=\"9.6%\"\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e43:44\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e35:37\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e28:23\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e52:52\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e23:23\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e60:60\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e60:60\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 44.95pt;border-top: none;border-right: none;border-left: none;border-image: initial;border-bottom: 1.5pt solid windowtext;padding: 0in 5.4pt;height: 49.3pt;vertical-align: top;\" valign=\"top\" width=\"9.6%\"\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e61.4 ± 9.2: 63.2 ± 7.7\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e59 : 62.5\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e64.3±9.1:65.2±9.1\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e61.5±7.2:63.7±6.8\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e62.8±6.1：60.2±8.1\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e61: 62.5\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e64.88±12.13:62.18±14.72\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 57.85pt;border-top: none;border-right: none;border-left: none;border-image: initial;border-bottom: 1.5pt solid windowtext;padding: 0in 5.4pt;height: 49.3pt;vertical-align: top;\" valign=\"top\" width=\"12.32%\"\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e29/14: 19/25\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e15/20: 18/20\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e13/15: 11/12\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e17/35: 22/30\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e8/15: 11/12\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e25/35: 28/32\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e24/36: 26/34\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 44.95pt;border-top: none;border-right: none;border-left: none;border-image: initial;border-bottom: 1.5pt solid windowtext;padding: 0in 5.4pt;height: 49.3pt;vertical-align: top;\" valign=\"top\" width=\"9.6%\"\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e30.7±5.4:29.1±5.0\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e27.7 \u0026nbsp; 28.3\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e31.1±5.1:30.4±3.6\u0026nbsp;\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e22.7±4.4:24.2±3.7\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e29.0±5.6:29.3±4.8\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003enot stated\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e24.3±53.1:25.58±2.83\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 43.15pt;border-top: none;border-right: none;border-left: none;border-image: initial;border-bottom: 1.5pt solid windowtext;padding: 0in 5.4pt;height: 49.3pt;vertical-align: top;\" valign=\"top\" width=\"9.28%\"\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eNO\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eNO\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eNO\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eNO\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eNO\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eNO\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"font-family: \n Verdana,Geneva,sans-serif;\"\u003e\u003cspan style=\"font-size: \n 10px;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003eNO\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp style=\"margin:0in;margin-bottom:.0001pt;text-align:justify;font-size:14px;font-family:\u0026quot;Calibri\u0026quot;,sans-serif;\"\u003e\u003cspan style=\"color: rgb(0, 0, 0); font-size: 10px; font-family: Verdana, Geneva, sans-serif;\"\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-musculoskeletal-disorders","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmsd","sideBox":"Learn more about [BMC Musculoskeletal Disorders](http://bmcmusculoskeletdisord.biomedcentral.com/)","snPcode":"","submissionUrl":"https://author-welcome.nature.com/12891","title":"BMC Musculoskeletal Disorders","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Total hip arthroplasty; surgical approach; direct anterior approach; posterior approach; early functional recovery.","lastPublishedDoi":"10.21203/rs.2.21945/v3","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.2.21945/v3","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground: \u003c/strong\u003eThe purpose of this systematic review and meta-analysis was to compare the direct anterior approach and posterior approach for primary total hip arthroplasty in terms of the clinical, functional and radiographic outcomes.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eMethods: \u003c/strong\u003eWe searched the PubMed and EMBASE databases and Cochrane Library from their inception to November 1, 2019. We searched for previously published articles and meta-analyses of randomized controlled trials.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e A total of 7 randomized controlled trials with 600 participants met the inclusion\u003c/p\u003e\u003cp\u003ecriteria. Among these patients, 301 and 299 were included in the DAA and PA groups, respectively. The DAA was associated with a longer surgery by a mean duration of 13.74 min (95% CI 6.88 to 20.61, p \u0026lt; 0.0001, I\u003csup\u003e2\u003c/sup\u003e=93%). The postoperative early functional outcomes were significantly better in the DAA group than in the PA group, such as the Visual Analogue Scale (VAS) score at 1 day postoperatively (MD=-0.65, 95% CI -0.91 to -0.38, p \u0026lt; 0.00001, I\u003csup\u003e2\u003c/sup\u003e=0%), VAS score at 2 days postoperatively (MD=-0.67, 95% CI -1.34 to -0.01, p =0.05, I\u003csup\u003e2\u003c/sup\u003e=88%) and Harris Hip Score (HHS) at 6 weeks postoperatively (MD=6.05, 95% CI 1.14 to 10.95, p =0.02, I\u003csup\u003e2\u003c/sup\u003e=52%). There was no significant difference between the DAA and PA groups in the length of the incision, hospital length of stay (LOS), blood loss, transfusion rates or complication rates. We found no significant difference between the two groups regarding late functional outcomes, such as the VAS score at 12 months postoperatively or the HHS scores at 3, 6, and 12 months postoperatively. A significant difference in the radiographic outcomes was not detected.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eConclusions: \u003c/strong\u003eThe\u003cstrong\u003e \u003c/strong\u003eDAA requires a longer surgery time than does the PA in primary total hip arthroplasty. The DAA yields better early functional recovery than does the PA. There was no significant difference between the two groups in terms of other clinical, complication-related, late functional or radiographic outcomes. The evidence on the superiority of the DAA is insufficient and needs to be studied further.\u003c/p\u003e","manuscriptTitle":"Clinical, Functional and Radiographic Outcomes of Primary Total Hip Arthroplasty between Direct Anterior Approach and Posterior Approach: a Systematic Review and Meta-analysis","msid":"","msnumber":"","nonDraftVersions":[{"code":3,"date":"2020-05-04 15:15:14","doi":"10.21203/rs.2.21945/v3","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Accept","date":"2020-04-27T12:00:00+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2020-04-20T12:00:00+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2020-04-19T12:00:00+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2020-04-19T12:00:00+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-musculoskeletal-disorders","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmsd","sideBox":"Learn more about [BMC Musculoskeletal Disorders](http://bmcmusculoskeletdisord.biomedcentral.com/)","snPcode":"","submissionUrl":"https://author-welcome.nature.com/12891","title":"BMC Musculoskeletal Disorders","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}},{"code":2,"date":"2020-03-27 10:57:49","doi":"10.21203/rs.2.21945/v2","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2020-04-13T12:00:00+00:00","index":2,"fulltext":"Recommendation: Accept without revision\nForm responses:\n---\n\nComments to Author:\n---\nDear authors!\n\nYou addressed every single point of suggested revisions. Therefore I would accept the manuscript in its current form.* Are the methods appropriate and well described?: **Yes**\n* Does the work include the necessary controls?: **Unable to assess**\n* Are the conclusions drawn adequately supported by the data shown?: **Yes**\n* Are you able to assess any statistics in the manuscript or would you recommend an additional statistical review?: **I am able to assess the statistics**\n* Quality of written English: **Acceptable**\n* Declaration of competing interests: **I declare that I have no competing interests.**\n* I agree to the open peer review policy of the journal. I understand that my name will be included on my report to the authors and, if the manuscript is accepted for publication, my named report including any attachments I upload will be posted on the website along with the authors' responses. I agree for my report to be made available under an Open Access Creative Commons CC-BY license (http://creativecommons.org/licenses/by/4.0/). I understand that any comments which I do not wish to be included in my named report can be included as confidential comments to the editors, which will not be published.: ** I agree to the open peer review policy of the journal**\n"},{"type":"decision","content":"Minor revision","date":"2020-04-13T12:00:00+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2020-04-08T12:00:00+00:00","index":1,"fulltext":"Recommendation: Accept after discretionary revisions\nForm responses:\n---\n\nComments to Author:\n---\n\n\nDear authors, the manuscript was corrected in accordance to the reviewers comments. However, there are still concerns about the correct english language of the manuscript. Such as:\nline 76: muscle gap, -is better : muscle interval\nline 85: ...meta-analysis but they are not comprenhensive or sufficiently accurate, please rephrase\npage 130: we dont need to write the full names of the reviewers in the manuscript\npage 224: 1 day and 2 days postoperative, please write: 1st and 2nd day\npage 270: ..with direct evidence that comprehensively compared the clinical results, what do you mean?\nPerhaps there are quite a lot language difficulties that must be adressed in the manuscript.\n\nAfter these minor corrections,I believe that the manuscript is ready to be published in the journal.* Are the methods appropriate and well described?: **Yes**\n* Does the work include the necessary controls?: **Yes**\n* Are the conclusions drawn adequately supported by the data shown?: **Yes**\n* Are you able to assess any statistics in the manuscript or would you recommend an additional statistical review?: **I recommend additional statistical review**\n* Quality of written English: **Needs some language corrections before being published**\n* Declaration of competing interests: **I declare that I have no competing interests'**\n* I agree to the open peer review policy of the journal. I understand that my name will be included on my report to the authors and, if the manuscript is accepted for publication, my named report including any attachments I upload will be posted on the website along with the authors' responses. I agree for my report to be made available under an Open Access Creative Commons CC-BY license (http://creativecommons.org/licenses/by/4.0/). I understand that any comments which I do not wish to be included in my named report can be included as confidential comments to the editors, which will not be published.: ** I agree to the open peer review policy of the journal**\n"},{"type":"reviewerAgreed","content":"","date":"2020-03-30T12:00:00+00:00","index":3,"fulltext":""},{"type":"editorInvitedReview","content":"","date":"2020-03-30T12:00:00+00:00","index":3,"fulltext":"Recommendation: Accept without revision\nForm responses:\n---\n\nComments to Author:\n---\nThe authors accepted all the points that were relevant and they corrected them properly. I have no other observation to do* Are the methods appropriate and well described?: **Yes**\n* Does the work include the necessary controls?: **No**\n* Are the conclusions drawn adequately supported by the data shown?: **Yes**\n* Are you able to assess any statistics in the manuscript or would you recommend an additional statistical review?: **I am able to assess the statistics**\n* Quality of written English: **Acceptable**\n* Declaration of competing interests: **I declare that I have no competing interests**\n* I agree to the open peer review policy of the journal. I understand that my name will be included on my report to the authors and, if the manuscript is accepted for publication, my named report including any attachments I upload will be posted on the website along with the authors' responses. I agree for my report to be made available under an Open Access Creative Commons CC-BY license (http://creativecommons.org/licenses/by/4.0/). I understand that any comments which I do not wish to be included in my named report can be included as confidential comments to the editors, which will not be published.: ** I agree to the open peer review policy of the journal**\n"},{"type":"reviewerAgreed","content":"","date":"2020-03-26T12:00:00+00:00","index":2,"fulltext":""},{"type":"reviewerAgreed","content":"","date":"2020-03-25T12:00:00+00:00","index":1,"fulltext":""},{"type":"editorAssigned","content":"","date":"2020-03-24T12:00:00+00:00","index":"","fulltext":""},{"type":"reviewersInvited","content":"","date":"2020-03-24T12:00:00+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2020-03-23T12:00:00+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2020-03-23T12:00:00+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-musculoskeletal-disorders","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmsd","sideBox":"Learn more about [BMC Musculoskeletal Disorders](http://bmcmusculoskeletdisord.biomedcentral.com/)","snPcode":"","submissionUrl":"https://author-welcome.nature.com/12891","title":"BMC Musculoskeletal Disorders","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}},{"code":1,"date":"2020-01-27 21:46:08","doi":"10.21203/rs.2.21945/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Minor revision","date":"2020-03-07T12:00:00+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2020-02-23T12:00:00+00:00","index":1,"fulltext":"Recommendation: Accept after minor essential revisions\nForm responses:\n---\n\nComments to Author:\n---\nThis is a very interesting manuscript regarding the comparison between the DAA and the PA for total hip arthroplasty. The important point of this work is that the authors have done a meta-analysis only with randomized control trials (RCT) studies and they also not include in their meta-analysis studies with piriformis preserving approaches, mini posterior approach or computer-aided techniques. So they tried to minimized the heterogeneity of the data. They found that there is not significant difference between the 2 groups of approaches in terms of clinical, complication, late functional and radiographic results. Although they found that DAA needs longer surgery time, however offer better functional early results than PA. However there is extensive literature regarding the comparison between these (2) approaches (DAA and PA) , even meta-analysis with RCT , such as : \" of A systematic review and meta-analysis of direct anterior approach versus posterior approach in total hip arthroplasty. \" of Zhao Wang et al. Journal of Orthopaedic Surgery and Research volume 13. I would expect the authors to make a comment, and emphasized the originality of their study.* Are the methods appropriate and well described?: **Yes**\n* Does the work include the necessary controls?: **Yes**\n* Are the conclusions drawn adequately supported by the data shown?: **Yes**\n* Are you able to assess any statistics in the manuscript or would you recommend an additional statistical review?: **I recommend additional statistical review**\n* Quality of written English: **Acceptable**\n* Declaration of competing interests: **I declare that I have no competing interests**\n* I agree to the open peer review policy of the journal. I understand that my name will be included on my report to the authors and, if the manuscript is accepted for publication, my named report including any attachments I upload will be posted on the website along with the authors' responses. I agree for my report to be made available under an Open Access Creative Commons CC-BY license (http://creativecommons.org/licenses/by/4.0/). I understand that any comments which I do not wish to be included in my named report can be included as confidential comments to the editors, which will not be published.: ** I agree to the open peer review policy of the journal**\n"},{"type":"editorInvitedReview","content":"","date":"2020-02-20T12:00:00+00:00","index":4,"fulltext":"Recommendation: Reviewer's comments unavailable pending editorial decision\n"},{"type":"editorInvitedReview","content":"","date":"2020-02-20T12:00:00+00:00","index":3,"fulltext":"Recommendation: Accept after discretionary revisions\nForm responses:\n---\n\nComments to Author:\n---\nThe manuscript reviewed (Clinical, Functional and Radiographic Outcomes of Primary Total Hip Arthroplasty between Direct Anterior Approach and Posterior Approach: a Systematic Review and Meta-analysis) is a systematic review and meta-analysis that attempts to evaluate the clinical, functional and radiographic outcomes of primary total hip arthroplasty between the direct anterior approach (DAA) and posterior approach (PA). The initial selection included 969 papers but only 7 RCT studies meet the eligibility criteria and are finally selected, for a total of 600 patients (301 in DAA and 299 in PA). It was found that early functional outcomes (evaluated trough VAS and Harris Hip Score (HHS)) were significantly better in the DAA group than in the PA group, while late functional outcomes were not significantly different between the two groups. There was also no significant difference between the DAA and PA groups at length of incision, length of stay, blood loss, transfusion rates or complication rates. No difference in radiographic outcomes was detected.\nThis paper is interesting because to my knowledge it is the first systematic review with a meta-analysis that does not include other different approaches (like minimally invasive approach or piriformis preserving approach) and that includes only randomized control trials. Globally the paper is extremely good. There are only minor concerns:\n1) In the manuscript, you run many different significance tests. The problem of multiple comparisons is well known in RCT research but its effects also systematic review. Doing such there is the risk of increasing type 1 error. The correction for multiple comparison procedures is difficult in systematic reviews (see Bender et al 2008 for more on that), and the procedures for simultaneous statistical inference in single studies cannot be transferred automatically for dealing with multiplicity in systematic reviews. The simple Bonferroni procedure, which would be feasible also in systematic reviews, rarely represents an adequate solution to the problem of multiple comparisons. Fortunately, most of your tests, in this paper, are not significant and then there is no risk of inflating type 1 error. Moreover, the significant results of comparisons are imitated only to one \"dimension\", the early functional outcome, making this result trustable. Considering that there is no easy way to correct for multiplicity in the systematic review and that it is probably not needed here, I suggest only to acknowledge for that, without other change, in \"limitation\" section (see again Bender 2008 for more details).\n2) The sentence \"The approach by minimally invasive, piriformis preserving approaches and computer-aided technology is also regarded as a standard approach in the study improperly, which should be avoided strictly for an accurate result.\" It is not easily understandable and should be reviewed.\n3) I suggest to add at the end of the sentence of \"It's hard to achieve blindness for doctors in surgery, but we think the detection bias outcome is unlikely to be affected by the absence of blindness\" somethings like\" at least in some outcome parameters \"because VAS could probably be affected.\nAs final, absolutely minor personal point, I don't like the use of the verb \"to incline\" in the way you do. For example, in \"DAA inclined to a significantly longer surgery time\". It's formally correct but it makes it less smooth to read.\nGlobally the paper is very good and we need more like that. Congratulations\n* Are the methods appropriate and well described?: **Yes**\n* Does the work include the necessary controls?: **Yes**\n* Are the conclusions drawn adequately supported by the data shown?: **Yes**\n* Are you able to assess any statistics in the manuscript or would you recommend an additional statistical review?: **I am able to assess the statistics**\n* Quality of written English: **Needs some language corrections before being published**\n* Declaration of competing interests: **I declare that I have no competing interests**\n* I agree to the open peer review policy of the journal. I understand that my name will be included on my report to the authors and, if the manuscript is accepted for publication, my named report including any attachments I upload will be posted on the website along with the authors' responses. I agree for my report to be made available under an Open Access Creative Commons CC-BY license (http://creativecommons.org/licenses/by/4.0/). I understand that any comments which I do not wish to be included in my named report can be included as confidential comments to the editors, which will not be published.: ** I agree to the open peer review policy of the journal**\n"},{"type":"reviewerAgreed","content":"","date":"2020-02-03T12:00:00+00:00","index":5,"fulltext":""},{"type":"editorInvitedReview","content":"","date":"2020-02-03T12:00:00+00:00","index":2,"fulltext":"Recommendation: Reject\nForm responses:\n---\n\nComments to Author:\n---\nDear authors!\n\nYour study reports on data comparing the direct anterior approach to the posterior approach for total hip replacement. Aim of your study was to perform a meta-analysis from already published trails. After review of your paper I have several concerns. I would like to point out some shortcomings and I have some suggestions to improve your study/manuscript:\n\n- Background: Line 69-70: THA is not \"kind of successful and effective treatment\"! THA is the gold standard treatment of end stage hip OA. Please rephrase.\n- Line 73-75: rephrase. Kind of is not a scientific english.\n- Methods: Line 94: plural! Meta-analyses AND were\n- Line 125: not clear. Please rephrase\n- Line 126: comparing instead of compared\n- Line 126 and 127: rephase. In example: Duplicates were removed\n- Line 127: please clarify: what are obvious irrelevant studies?\n- Line 128: why did you exclude minimally invasive? The DAA is a minimally invasive approach\n- Line 129: You have to adhere strictly to clear inclusion and exclusion criteria. It is unclear what you mean by improper studies.\n- Line 132: accuracy instead of accurate\n- Line 132: what do you mean by surgeon number? Number of surgeons?\n- Line 133: what do you mean by learning cases?\n- Line 153: forest plots instead of maps\n- In general: don't mix the present and past tense during writing!!!!\n- Results: Line 161-162: All the studies were not learning cases - this is not an English sentence.\n- Line 200: correct: .And\n- In general: there are too many figures and outcome parameters in the results section. You should focus on some key-points.\n- Radiographic outcomes: I think you mean post-opeartive angles instead of pre-opeartive. Otherwise it makes no sense.\n- Discussion: Line 269: again use plural for meta-analyses\n\n- Furthermore, I advise you to review your manuscript regarding the english wording and phrasing. The paper is not written in a proper scientific english. Another major drawback is the lack of a clear description of the inclusion and exclusion criteria.\n\nUnfortunately, there are too many major drawbacks of this manuscript at the time. The statistical analysis of the meta-analysis has been performed in a proper manner. The Background, Methods and Discussion section has to be revised tremendously. This is even too much for a major revision. Therefore I would not recommend it for publication in BMC Musculoskeletal Disorders.\n\n* Are the methods appropriate and well described?: **No**\n* Does the work include the necessary controls?: **Unable to assess**\n* Are the conclusions drawn adequately supported by the data shown?: **No**\n* Are you able to assess any statistics in the manuscript or would you recommend an additional statistical review?: **I am able to assess the statistics**\n* Quality of written English: **Not suitable for publication unless extensively edited**\n* Declaration of competing interests: **I declare that I have no competing interests.**\n* I agree to the open peer review policy of the journal. I understand that my name will be included on my report to the authors and, if the manuscript is accepted for publication, my named report including any attachments I upload will be posted on the website along with the authors' responses. I agree for my report to be made available under an Open Access Creative Commons CC-BY license (http://creativecommons.org/licenses/by/4.0/). I understand that any comments which I do not wish to be included in my named report can be included as confidential comments to the editors, which will not be published.: ** I agree to the open peer review policy of the journal**\n"},{"type":"reviewerAgreed","content":"","date":"2020-01-31T12:00:00+00:00","index":4,"fulltext":""},{"type":"reviewerAgreed","content":"","date":"2020-01-30T12:00:00+00:00","index":3,"fulltext":""},{"type":"reviewerAgreed","content":"","date":"2020-01-28T12:00:00+00:00","index":2,"fulltext":""},{"type":"editorAssigned","content":"","date":"2020-01-27T12:00:00+00:00","index":"","fulltext":""},{"type":"reviewersInvited","content":"","date":"2020-01-27T12:00:00+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2020-01-27T12:00:00+00:00","index":1,"fulltext":""},{"type":"checksComplete","content":"","date":"2020-01-23T12:00:00+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2020-01-22T12:00:00+00:00","index":"","fulltext":""},{"type":"submitted","content":"","date":"2020-01-19T12:00:00+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-musculoskeletal-disorders","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmsd","sideBox":"Learn more about [BMC Musculoskeletal Disorders](http://bmcmusculoskeletdisord.biomedcentral.com/)","snPcode":"","submissionUrl":"https://author-welcome.nature.com/12891","title":"BMC Musculoskeletal Disorders","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"c2e9def1-a70a-49ec-8d4f-d49f2f4f5087","owner":[],"postedDate":"May 4th, 2020","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":93375,"name":"Orthopedics"}],"tags":[],"updatedAt":"2021-07-22T20:13:15+00:00","versionOfRecord":{"articleIdentity":"rs-12527","link":"https://doi.org/10.1186/s12891-020-03318-x","journal":{"identity":"bmc-musculoskeletal-disorders","isVorOnly":false,"title":"BMC Musculoskeletal Disorders"},"publishedOn":"2020-06-02 20:13:15","publishedOnDateReadable":"June 2nd, 2020"},"versionCreatedAt":"2020-05-04 15:15:14","video":"","vorDoi":"10.1186/s12891-020-03318-x","vorDoiUrl":"https://doi.org/10.1186/s12891-020-03318-x","workflowStages":[]},"version":"v3","identity":"rs-12527","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"identity":"rs-12527","version":["v3"]},"buildId":"7rjqhiLT3MXkJMwkYKINL","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}